The high-melting fractions of lauric oils, e.g. palm kernel oil, are known as cocoa butter substitutes (CBS). They are used as ingredients in confectioneries, suppositories, lip balms, etc.
Lauric CBSs solidify in a stable crystal form, which does not require a complicated “tempering”. Tempering is the controlled formation of a sufficient number of stable seed crystals that ultimately produce the desired crystal form during solidification. Some of the main drawbacks are low cocoa butter tolerance, and when used as filling fat it will migrate into the surrounding chocolate shell, eventually leading to bloom. Furthermore, when exposed to moisture and if fat splitting enzymes are present, there is a risk of hydrolysis giving the product an undesirable, soapy flavour.
Non-lauric, non-temper alternatives to CBSs are trans-hydrogenated and, usually, fractionated triglyceride mixtures based on soybean oil, rapeseed oil, sunflower oil, palm oil or other similar oils and fats. They are known as non-lauric CBSs or cocoa butter replacers (CBR) with a fair cocoa butter tolerance. They are non-temper fats, but they have a slower solidification rate than lauric CBS. Furthermore, they suffer from the drawback of containing trans fatty acids in the glycerides that are suspected of increasing the blood cholesterol level and the risk of coronary heart disease if contained in the diet. As a result of this, consumers are increasingly looking for foods without these fatty acids.
Non-trans, non-lauric alternatives are cocoa butter (CB) and cocoa butter equivalents (CBE). The production of CBEs is based on fractions of fats containing the same triglycerides as CB, e.g. palm oil, shea butter, illipe, etc. The main part of the triglycerides is of the symmetric SUS type (S=saturated fatty acids, U=unsaturated fatty acids) or more specifically, StOSt, POSt and POP (P=palmitic acid, St=stearic acid, O=oleic acid).
CB and CBE exist in a number of polymorphic forms, and the nature of the crystalline form depends on the method of cooling of the liquid fat. If the fat is allowed to crystallise in an unstable form, it recrystallises after a time delay. In the production of chocolate this transformation will cause a change from a nice glossy chocolate to a dull or mouldy looking chocolate. This phenomenon, “fat-bloom”, is avoided by tempering of the chocolate. In the tempering process the liquid chocolate is cooled down to produce both stable and unstable crystals followed by heating to a temperature above the melting point of the unstable crystals, leaving only stable seed crystals.
Tempering is a complicated and expensive process, and consequently there is a need for fat compositions that do not require tempering and do not contain lauric and trans fatty acids.